Pharmaceutical composition for treatment and prevention of chronic disease

ABSTRACT

An object of the present invention is to develop a novel treatment method for chronic diseases for which conventional treatment methods are either ineffective or for which efficacy is low. The present invention provides a pharmaceutical composition for the treatment and/or prevention of an inflammatory chronic disease that is used in combination with a biological preparation that inhibits leukocyte tissue invasion. The pharmaceutical composition of the present invention contains as an active ingredient thereof siRNA suppressing the expression of CHST15 gene that contains a structure formed by the hybridization of RNA containing the base sequence represented by SEQ ID NO: 1 with RNA complementary thereto.

TECHNICAL FIELD

The present invention relates to a pharmaceutical composition comprising as active ingredients thereof siRNA and a DNA vector capable of expressing that siRNA, and more particularly, relates to inhibition of expression of human CHST15, a pharmaceutical composition comprising as active ingredients thereof siRNA and a DNA vector capable of expressing that siRNA, the use thereof, and an administration method.

BACKGROUND ART

Many chronic diseases are autoimmune diseases that ae associated with chronic inflammation. In recent years, attention has focused on the invasion of tissue by leukocytes involved in inflammation as a novel treatment target for these chronic diseases. The invasion of inflammatory tissue by leukocytes circulating in the blood consists of the four stages indicated below. Namely, (1) decrease in leukocyte flow rate due to a first interaction between vascular endothelial cells and leukocytes in the vicinity of the inflammation site (rolling), (2) activation of rolling leukocytes, (3) strong adhesion of the aforementioned activated leukocytes to the aforementioned vascular endothelial cells due to a second interaction in the vicinity of the inflammation site, and (4) final migratory invasion of the aforementioned activated leukocytes into tissue by slipping through blood vessels by passing between vascular endothelial cells. Among these stages, bonding between L-selectin on the surface of the leukocytes and the end of a 6-sulfosiallyl Lewis X-type sugar chain of L-selectin ligand present on the surface of vascular endothelial cells is known to be involved in the first stage rolling. N-acetylglucosamine-6-sulfotransferase is known to be involved as the enzyme involved in inflammation site-specific synthesis of this 6-sulfosiallyl Lewis X-type sugar chain, and the sulfotransferase encoded by human CHST2 and CHST4 genes has conventionally been thought to be involved in invasion of inflammatory tissue by leukocytes circulating in the blood. However, based on research conducted on knockout mice, although circulating leukocytes invade inflammatory tissue even in mice lacking both CHST2 and CHST4 genes, the reason for this has not been clearly determined (Non-Patent Document 1).

The inventors of the present invention reported therapeutic effects, including inhibition of ulceration, inflammation and fibrosis, using siRNA expressing sulfotransferase CHST15 that is different from CHST2 and CHST4 (Patent Documents 1 to 3 and Non-Patent Documents 1 and 2). In particular, a phase IIa clinical trial was recently conducted on human Crohn's disease patients, and it was demonstrated that when the aforementioned siRNA was administered by submucosal administration into the large intestine of these patients, healing of the mucosa or healing of ulceration was able to be achieved endoscopically.

During the course thereof, since siRNA therapy using CHST15 yields superior treatment results in comparison with conventional biological preparation therapy for Crohn's disease, it was found that siRNA of CHST15 inhibits the first stage of invasion of inflammatory tissue by circulating leukocytes, thereby leading to completion of the present invention.

PRIOR ART DOCUMENTS Patent Documents

-   [Patent Document 1] International Publication No. WO 2009/004995 -   [Patent Document 2] International Publication No. WO 2009/084232 -   [Patent Document 3] International Publication No. WO 2014/013535

Non-Patent Documents

-   [Non-Patent Document 1] Patnode, M. L., et al., Glycobiology, 23:     381-394 (2013) -   [Non-Patent Document 2] Kiryu, H., et al., Bioinformatics, 27:     1788-1797 (2011) -   [Non-Patent Document 3] Suzuki, K., et al., Su1078 Gastroenterology     204: (suppl.)

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

It is necessary to develop a novel treatment method for chronic disease for which conventional treatment methods are either ineffective or for which efficacy is low.

Means for Solving the Problems

Since siRNA that inhibits expression of CHST15 inhibits expression of 6-sulfosiallyl Lewis X of the L-selectin ligand of vascular endothelial cells at an inflammation site, a novel technology for chronic disease was developed using the aforementioned siRNA that can be used in combination with conventional therapy.

The present invention provides a pharmaceutical composition for the treatment and/or prevention of an inflammatory chronic disease that is used in combination with a biological preparation inhibiting leukocyte tissue invasion and/or a biological preparation inhibiting inflammatory cytokines. The pharmaceutical composition of the present invention contains as active ingredients thereof:

(i) siRNA suppressing the expression of CHST15 gene that contains a structure formed by the hybridization of RNA containing the base sequence represented by SEQ ID NO: 1 with RNA containing the base sequence complementary thereto,

(ii) the siRNA of (i) having a structure in which one or a plurality of nucleic acids overhang from the end thereof, or

(iii) a DNA vector capable of expressing the siRNA of (i) or (ii).

In the pharmaceutical composition of the present invention, the biological preparation inhibiting leukocyte tissue invasion may inhibit the function of at least one molecule selected from the group consisting of integrin and/or chemokine receptor on the surface of leukocytes circulating in the blood and adhesion molecules on the surface of vascular endothelial cells.

In the pharmaceutical composition of the present invention, the biological preparation inhibiting leukocyte tissue invasion may be at least one member selected from the group consisting of Etrolizumab, Vedolizumab, Natalizumab, PF-00547659 and Vercirnon.

In the pharmaceutical composition of the present invention, the biological preparation inhibiting inflammatory cytokines may inhibit the function of at least one molecule selected from the group consisting of TNF-α, IL-17 and IL-23.

The pharmaceutical composition of the present invention may further use in combination at least one member selected from the group consisting of a 5-aminosalicyclic acid preparation, steroid preparation, thiopurine preparation, and immunosuppressants including tacrolimus.

The present invention provides a pharmaceutical composition for the treatment and/or prevention of chronic disease in which 6-sulfosiallyl Lewis X of L-selectin ligand is expressed on the surface of the vascular endothelial cells of a patient. The pharmaceutical composition of the present invention contains as active ingredients thereof:

(i) siRNA suppressing the expression of CHST15 gene that contains a structure formed by the hybridization of RNA containing the base sequence represented by SEQ ID NO: 1 with RNA containing the base sequence complementary thereto,

(ii) the siRNA of (i) having a structure in which one or a plurality of nucleic acids overhang from the end thereof, or

(iii) a DNA vector capable of expressing the siRNA of (i) or (ii).

In the pharmaceutical composition of the present invention, the chronic disease may be an autoimmune disease.

In the pharmaceutical composition of the present invention, the autoimmune disease may be at least one disease selected from the group consisting of inflammatory colitis, Crohn's disease, ulcerative colitis, autoimmune pancreatitis, chronic rheumatoid arthritis, bronchial asthma, chronic interstitial pneumonia, Grave's disease, Hashimoto's thyroiditis, chronic thyroiditis and atopic dermatitis.

The pharmaceutical composition of the present invention may be administered systemically or locally.

In the pharmaceutical composition of the present invention, the autoimmune disease may be selected from the group consisting of inflammatory colitis, Crohn's disease and ulcerative colitis, and the local administration may be submucosal administration into the intestine of a patient.

In the pharmaceutical composition of the present invention, the systemic administration may be oral administration and/or intravenous injection.

In the pharmaceutical composition of the present invention, a complex may be administered orally that contains N-acetylated chitosan and an active ingredient in the form of:

(i) siRNA suppressing expression of CHST15 gene that contains a structure obtained as a result of hybridization of RNA containing the base sequence represented by SEQ ID NO: 1 with RNA containing the base sequence complementary thereto, or

(ii) the siRNA of (i) having a structure in which one or a plurality of nucleic acids overhang from the end thereof.

All publications mentioned in the present description are incorporated in the present description in their entirety by reference.

In the present invention, “administering in combination” refers to the administration of the pharmaceutical composition of the present invention which is administered simultaneously, continuously or after allowing an certain period of time after having administration of the other, a biological preparation that inhibits tissue invasion by leukocytes and/or a biological preparation that inhibits inflammatory cytokines, optionally 5-aminosalicylic acid, steroid preparations, thiopurine preparations and immunosuppressants. In the case of administering a biological preparation that inhibits tissue invasion by leukocytes and/or a biological preparation that inhibits inflammatory cytokines, and optionally at least one member selected from the group consisting of 5-aminosalicylic acid, steroid preparations, thiopurine preparations and immunosuppressants, and the pharmaceutical composition of the present invention, overlapping of the administration period of the pharmaceutical composition of the present invention and the administration period of either of the aforementioned biological preparations, or administration of the pharmaceutical composition of the present invention within a period equal to at least 20% of the administration period of the biological preparation following completion of the administration period of the biological preparation, is included in “administration in combination”. Although the dose of the pharmaceutical composition of the present invention can be suitably adjusted according to such factors as body weight, age and symptoms of the subject to receive administration, in the case, for example, the biological preparation is an antibody, the dose is, for example, 0.1 mg/kg/week to 100 mg/kg/week or a dose that yields a blood concentration equivalent thereto, preferably 1 mg/kg/week to 50 mg/kg/week or a dose that yields a blood concentration equivalent thereto, and more preferably 5 mg/kg/week to 10 mg/kg/week or a dose that yields a blood concentration equivalent thereto. In addition, when the antimetabolite is gemcitabine hydrochloride, the dose is, for example, 10 mg/m²/week to 10000 mg/m²/week or a dose that yields a blood concentration equivalent thereto, preferably 100 mg/m²/week to 5000 mg/m²/week or a dose that yields a blood concentration equivalent thereto, and more preferably 500 mg/m²/week to 1500 mg/m²/week or a dose that yields a blood concentration equivalent thereto.

An administration method, administration interval and dose that yield a therapeutic effect similar to the effect of the present invention can be suitably selected for the aforementioned administration method, administration interval and dose. For example, an administration method, administration interval and dose that yield an effect similar to that of the aforementioned preferable examples can be selected by measuring the blood concentrations of a biological preparation that inhibits tissue invasion by leukocytes and/or a biological preparation that inhibits inflammatory cytokines, at least one member selected from the group consisting of 5-aminosalicylic acid, steroid preparations, thiopurine preparations and immunosuppressants depending on the case, and the pharmaceutical composition of the present invention, and an administration method, administration interval and dose that achieve a blood concentration equivalent to that of the aforementioned examples are included in the present invention.

In the present description, examples of diseases used for treatment and/or prevention by the pharmaceutical composition of the present invention include, but are not limited to, Guillain-Barré syndrome, myasthenia gravis, chronic gastritis, chronic atrophic gastritis, autoimmune hepatitis, primary biliary cholangitis, inflammatory bowel disease, Crohn's disease, ulcerative colitis, autoimmune pancreatitis, Takayasu's arteritis, Goodpasture's syndrome, rapidly progressive glomerulonephritis, Grave's disease, Hashimoto's thyroiditis, primary hypothyroidism, idiopathic Addison's disease, type 1 diabetes, chronic discoid lupus erythematosus, localized scleroderma, pemphigus, pustular psoriasis, psoriasis vulgaris, acquired epidermolysis bullosa, autoimmune optic neuropathy, chronic rheumatoid arthritis, systemic lupus erythematosus, scleroderma, polymyositis, dermatomyositis, vasculitis syndrome, mixed connective tissue disease, bronchial asthma, chronic thyroiditis and atopic dermatitis.

A detailed explanation of the present invention and its examples are also explained by the following references included in the submitted documents of the present application and documents cited therein.

In particular, references consisting of Suzawa, K., et al., Am. J. Gastroenterol. 2007; 102: 1499-1509, Yeh, J. C., et al., Cell, 2001; 105: 957-969, Kobayashi, M., et al., Biol. Pharm. Bull. 2009; 32: 774-779, and A. van Zante and S. D. Rosen, Biochemical Society Transactions 2003; 31: 313-317 are incorporated in their entirety in the present description by reference.

8. Study Design and Planned Sample Size

8.1 Study Design

This is a randomized, double-blinded, placebo-controlled, parallel group study or STNM01 by a single dose submucosal injection.

Freeze-dried STNM01 will be diluted with physiological saline. Study drugs will be administered submucosally using an endoscope to the rectosigmioidal region. The patients will be randomized to receive either STNM01 (in concentrations of 25 nM and 250 nM) or placebo. Eligible subjects will be admitted to the study sites and receive a single dose of the study drug on Day 1. Subjects will be discharged alter confirming that there are no safety concerns on Day 2. They will return to the study sites for follow-up examinations 14 and 28 days after administration.

Table 8-1 shows the dose (concentration), dosage regimen and number of subjects.

TABLE 8-1 Dose (Concentration), Dosage Regimen and Number of Subjects Group 1 2 3 Study drug STNM01 STNM01 Placebo Concentration 25  250  — (nM) Number of 8 8 8 subjects Number of Single administration administration Dosage The study drug will be submucosally regimen injected using an endoscope and an endoscope puncture needle (22 G) to the rectosigmoidal region including any narrowed lesion. Volume Maximum of 2 mL/site by one injection, maximum of 16 mL/one lesion in total (8 sites from 35 cm to 5 cm the lesion in total as explained on section 10 5.2, scheme 10 1: SIC002 Injection model)

<Rationale>

Local administration of STNM01 (including 25 nM and 250 nM) in the completed randomized, double-blind, placebo-controlled Phase 1 clinical study was generally well tolerated. Therefore, there is no safety concern that would prevent the conduct of the proposed, parallel group Phase 2a clinical study at this point of time. Mucosal healing efficacy observed in the Phase 1 study was unexpected as the primary objective of the Phase 1 study was to evaluate safety. Thus, the planned Phase 2a study is intended to confirm the efficacy observed in the Phase 1 study and to gain more information about efficacy parameters and the doses to be used in a larger controlled next study to be performed. Although this is a parallel group-comparison design, safety of the patients will be closely monitored and will be assessed as a secondary endpoint.

8.2 Discontinuation or Interruption of the Study

When one or more subjects in the current step experienced a serious or a severe adverse event which is considered to have been caused by factors other than the study drug, e.g., a study procedure, or, when half or more of the subjects in the current step experienced a moderate adverse event requiring medical intervention which is considered to have been caused by factors other than the study drug, the sponsor will temporarily discontinue the study and review the study continuation in reference to the principal investigator's opinion.

8.3 Planned Sample Size

A two group Chi-Square test with a 0.050 two-sided significance level will have 80% power to detect the difference between active treatment and placebo (89% versus 11%) when the sample size in each group is 8 (assuming a withdrawal rate of 15%).

Therefore, eight subjects per group (8 for STNM01 25 nM, 8 for STNM01 250 nM, 8 for placebo), 24 subjects in total will be included.

8.4 Planned Duration of Study

May 2013 to May 2016

8.5 Discussion of Study Design and Choice of Control Groups

This is a P2a study to investigate the safety and efficacy of a single dose of STNM01. The design of the study is deemed appropriate for this type of study.

9. Selection and Discontinuation/Withdrawal of Subjects

Participation in the study will be offered to all patients who are eligible according to the inclusion and exclusion criteria, who are patients of or referred to the participating institutions and who are presented to the study investigators.

9.1 Indication

Patients with Ulcerative Colitis with endoscopic active lesion(s).

9.2 Inclusion and Exclusion Criteria

9.2.1 Inclusion Criteria

Subject eligibility is determined according to the following criteria.

-   1) Male/female -   2) The subject is a patient with Ulcerative colitis with active     lesion(s). -   3) The subject has been treated for more than 2 months before the     screening tests by conventional drug(s) generally used to treat     Ulcerative colitis [e.g., 5-aminosalicylic acid agent, steroid,     immunoregulating agent, biological agent (e.g. anti-TNF antibody or     Vedolizumab need a wash out period of 4 weeks)]. In the opinion of     his primary doctor, the subject has experienced an insufficient     response or resistance to one of the current conventional treatment     options. The subject's insufficient response or resistance to the     current treatment is also confirmed by the principal investigator of     this study, based on the screening tests including endoscopic     examination, clinical examination and laboratory tests. The     subject's experiencing an “insufficient response or resistance” can     be assessed at the primary doctor's and principal investigator's     discretion; however, use of one prescribed medication and     insufficient therapeutic effect by the medication(s) at present     should be documented in the subject's medical record -   4) The subject has little difficulty with the introduction of an     endoscope, e.g., he has little stenosis or, if any, the diameter of     the narrowed lesion is 14 mm or more. -   5) Endoscopic Mayo score at screening has to be 1 or above 1. -   6) The subject's age is 18 or older and under 65 at the time of     informed consent. -   7) The subject signs and dates a written informed consent to     participate to the study.

<Rationales>

-   2) The endoscopic severity of UC should be moderate to severe     because the study requires inpatient treatment with the study drug     and outpatient visits. -   3) This is intended to investigate the efficacy and safety of the     study drug when administered concomitantly with conventional     treatments. -   4,5) This is intended to perform the study in compliance with the     protocol. -   6 The age range was selected to recruit legal adults who are capable     of giving informed consent. -   7) This is in compliance with the GCP.

9.2.2. Exclusion Criteria

Any subject who meets any of the following criteria will not qualify for entry into the study:

-   1) 1) The subject has or has a history of serious cardiac,     hematological or pulmonary disease, and is unsuitable, in the     investigator's opinion, to participate in the study. -   2) The subject has a history of complete colon resection surgery for     Ulcerative colitis. -   3) The subject has a complication of Ulcerative colitis such as     severe bleeding or intestinal adhesions to other organs, and is     unsuitable, in the investigator's opinion, to participate in the     study. -   4) The subject has an anal stenosis that affects defecation     frequency, or perianal abscess with fever. However, the subject is     eligible if his bowel movement has been improved by Seton method. -   5) The subject has an obviously reduced general condition. -   6) The subject in whom large parts of the colon are affected     (pancolitis) -   7) The subjects who are expected to evince an indication for     colectomy during the study participation. -   8) The subject is currently receiving total parenteral nutrition. -   9) The subject has a hepatic impairment or renal disorder, and is     unsuitable, in the investigator's opinion, to participate in the     study. -   10) The subject has or has a history of malignant tumor within the     past 5 years. -   11) The subject has or has a history of abdominal phthisis. -   12) The subject has a complication of serious infection that     requires hospitalization. -   13) The subject should be excluded if he is currently treated with a     biological agent (e.g., anti-TNF-α antibody or Vedolizumab). -   14) The subject should be excluded if he is treated with concomitant     medication [e.g., 5-aminosalicytic acid agent, steroid,     immunoregulating agent] by local administration. -   15) The subject has a history of clinically serious allergic     symptom. “Serious” means an allergic symptom causing generalized     hives, anaphylaxis or shock requiting hospitalization, when exposed     to a specific antigen or drug. -   16) The subject has a history of HBV, HCV and/or HIV infection. -   17) The person has alcohol or drug dependency. -   18) The subject's conventional treatment for Ulcerative colitis has     been changed in its ‘quality’ (medication class) of therapy regimen     or added with a new treatment: no introduction of thiopurines the     previous 3 months, no change of dosing 5-ASA or corticosteroids     within 14 days prior to the study drug administration. -   19) The subject is currently participating or plans to participate     in another clinical study during the course of this study. -   20) The subject received administration of any other investigational     product within 6 months prior to the informed consent for this     study. -   21) The subject has any psychiatric or neurological disorder, and is     unsuitable, in the investigator's opinion, to participate in the     study. -   22) The subject is incapable of or restricted to the     protocol-directed examinations or procedures. -   23) The subject is considered by the investigator, for any other     reason, to be unsuitable for participating in this study. -   24) Not willing and able to use a reliable and acceptable     contraceptive method (Pearl Index<1) The subjects or their sexual     partners, respectively, must use at least one of these reliable     methods from 6 weeks before until 3 weeks after the administration     of the study medication. -   25) For females: pregnancy or lactation. -   26) Co-worker, student, relative or spouse of the investigator.

<Rationales>

-   1) to 20) These are intended to ensure the subject's safety and     exclude effects on the evaluation of safety and efficacy of the     study drug. -   21) These disease states are excluded since the evaluation of     efficacy requires reports of subjective symptoms from subjects which     may be interfered by psychiatric or nervous system disorder. -   22) This is intended to perform the study in compliance with the     protocol. -   23) This is intended to exclude individuals who are considered     inadequate medically or ethically to participate in the study for     reasons other than those described in 1) to 21).

9.3 Prior and Concomitant Medications and Therapies

-   1) Only systemic concomitant medication is allowed. The usage of     local administered background therapies is prohibited (e.g., 5-ASA,     steroid, immunoregulating agent, biological agent (e.g. anti-TNF-α     antibody or Vedolizumab need a washout period of 4 weeks). -   2) All medications that were used within 2 months prior to the study     drug administration through the end of study except the study drugs     should be documented including the name of the drug, purpose, daily     dose, dosage regimen, route of administration and start/stop dates     in the CRF. -   3) As for the medications to treat UC, medications that were used     before the period described in 1) above will be documented similarly     where possible. -   4) All therapies other than medications will be documented where     possible including the therapy, purpose, star/stop dates in the CRF. -   5) All medications and therapies to treat adverse events that were     used before the end of final observation/examination of this study     should be documented in the CRF. Use of medications and therapies     for emergency will not be handled as a protocol deviation.

<Rationale>

Concomitant use of prior medications and therapies with STNM01 in this study can be justified because there were very few toxic findings and the drug eliminated from blood rapidly after administration in the non-clinical studies of STNM01, thus we speculate that onset of unknown adverse drug reactions or increase in severity of adverse drug reactions of the prior medications will be unlikely.

9.4 Restrictions During the Study

Subjects must be instructed to follow the instructions below. They will stay under medical supervision of the investigator during hospitalization.

9.4.1 Food, Drinks, Smoking and Exercise

Subjects will start fasting after evening meal on Day 0 through 4 hours after study drug administration on Day 1. They will also start fasting after evening meal before the day of follow-up examinations until their completion.

Food and drinks containing alcohol and caffeine will be prohibited during hospitalization. After discharge, excessive drinking will be prohibited until the end of final examinations/observations. Alcohol beverages will not be allowed from the day before follow-up examinations until their completion.

Food and beverages other than those to be provided in the study site will not be allowed during hospitalization. Subjects must be instructed to refrain horn excessive earing and drinking after discharge until the end of final examinations/observations.

Smoking will be prohibited during hospitalization. Smoking will not be allowed from bedtime on the day before follow-up examinations until their completion.

Physical exercise will be prohibited while subjects are in the study site as well as from the day before follow-up examinations until their completion.

9.4.2 Contacts to Subjects after Discharge

The site management organization will contact the subjects in a timely manner prior to the scheduled visit regarding the study procedure they need to follow (e.g. restrictions on excessive eating and drinking after discharge).

9.5 Criteria for Discontinuation or Withdrawal of a Subject

if any of the following circumstances occurs, the investigator must discontinue the study drug administration to the subject immediately, provide him with appropriate treatments and perform the examinations/observations scheduled at the time of discharge as much as possible. Subjects prematurely withdrawn from the study may be replaced. The investigator will document the date of and reason for discontinuation, treatments given after discontinuation and clinical course thereafter in the CRF, which must be submitted to the sponsor without delay. If the scheduled examinations/observations were not performed at discontinuation, the reason must be documented in the CRF.

-   1) The subjcct withdrew consent. -   2) The subject failed to meet protocol entry criteria. -   3) The principal investigator judged that the subject would suffer a     loss if he continued his participation in the study.     -   (e.g., onset of adverse event requiring study termination,         aggravation of underlying disease) -   4) There was a major protocol deviation. -   5) The sponsor prematurely terminated the study. -   6) The principal investigator found it necessary to remove the     subject from the study for reasons other than those described above.

<Rationale>

-   1) This is one of the prerequisites to obtain informed consent. -   2) Subjects for whom appropriate evaluation cannot be made should be     removed from the study. -   3) This is intended to consider safety and ethics. -   4) Major protocol deviation is a violation of the GCP. -   5) This will be applied when the sponsor decided to prematurely     terminate or interrupt the overall study. -   6) This is intended to remove a subject from the study when the     principal investigator judges it necessary for reasons other than     those described above. 

1. A pharmaceutical composition for the treatment and/or prevention of a chronic disease that is used in combination with a biological preparation inhibiting leukocyte tissue invasion and/or a biological preparation inhibiting inflammatory cytokines; containing as an active ingredient thereof: (i) siRNA suppressing the expression of CHST15 gene that contains a structure formed by the hybridization of RNA containing the base sequence represented by SEQ ID NO: 1 with RNA containing the base sequence complementary thereto, (ii) the siRNA of (i) having a structure in which one or a plurality of nucleic acids overhang from the end thereof, or (iii) a DNA vector capable of expressing the siRNA of (i) or (ii).
 2. The pharmaceutical composition according to claim 1, wherein the biological preparation inhibiting leukocyte tissue invasion inhibits the function of at least one molecule selected from the group consisting of integrin and/or chemokine receptor on the surface of leukocytes circulating in the blood and adhesion molecules on the surface of vascular endothelial cells.
 3. The pharmaceutical composition according to claim 2, wherein the biological preparation inhibiting leukocyte tissue invasion is at least one member selected from the group consisting of Etrolizumab, Vedolizumab, Natalizumab, PF-00547659 and Vercirnon.
 4. The pharmaceutical composition according to any of claims 1 to 3, wherein the biological preparation inhibiting inflammatory cytokines inhibits the function of at least one molecule selected from the group consisting of TNF-α, IL-17 and IL-23.
 5. The pharmaceutical composition according to any of claims 1 to 4, further used in combination with at least one member selected from the group consisting of a 5-aminosalicyclic acid preparation, steroid preparation, thiopurine preparation and immunosuppressants.
 6. A pharmaceutical composition for the treatment and/or prevention of a chronic disease in which 6-sulfosiallyl Lewis X of L-selectin ligand is expressed on the surface of the vascular endothelial cells of a patient; containing as an active ingredient thereof: (i) siRNA suppressing the expression of CHST15 gene that contains a structure formed by the hybridization of RNA containing the base sequence represented by SEQ ID NO: 1 with RNA containing the base sequence complementary thereto, (ii) the siRNA of (i) having a structure in which one or a plurality of nucleic acids overhang from the end thereof, or (iii) a DNA vector capable of expressing the siRNA of (i) or (ii).
 7. The pharmaceutical composition according to any of claims 1 to 6, wherein the chronic disease is an autoimmune disease.
 8. The pharmaceutical composition according to claim 8, wherein the autoimmune disease is at least one disease selected from the group consisting of inflammatory colitis, Crohn's disease, ulcerative colitis, autoimmune pancreatitis, chronic rheumatoid arthritis, bronchial asthma, chronic interstitial pneumonia, Grave's disease, Hashimoto's thyroiditis, chronic thyroiditis and atopic dermatitis.
 9. The pharmaceutical composition according to any of claims 1 to 8, which is administered systemically or locally.
 10. The pharmaceutical composition according to claim 9, wherein the autoimmune disease is selected from the group consisting of inflammatory colitis, Crohn's disease and ulcerative colitis, and the local administration is submucosal administration into the intestine of a patient.
 11. The pharmaceutical composition according to claim 9, wherein the systemic administration is oral administration and/or intravenous injection.
 12. The pharmaceutical composition according to claim 11, wherein a complex is administered orally that contains an active ingredient and N-acetylated chitosan; wherein, the active ingredient is: (i) siRNA suppressing expression of CHST15 gene that contains a structure formed by the hybridization of RNA containing the base sequence represented by SEQ ID NO: 1 with RNA containing the base sequence complementary thereto, or (ii) the siRNA of (i) having a structure in which one or a plurality of nucleic acids overhang from the end thereof. 